There's a Lucid Dream Machinesleeping mask on Instructables that pulses LEDs in your eyelids four hours after you fall asleep, waking you up just enough to notice your dreams and control their outcomes. The mask requires a fair bit of soldering and programming experience, so it isn't for DIY luddites like me. Which is good, because my sleep is too precious and my dreams are too weird to want one of these anyway. [Instructables via Make]